Customers enter the camera department of a store at the average of a rate of six per hour. The department is staffed by one employee, who takes an average of six minutes to serve each arrival. Assume this is a simple Poisson arrival, and exponentially distributed service time situation

if the service time becomes fixed at six minutes per customer, how many people would you expect to see in the camera department (excluding the clerk)? How long would a customer expect to spend in the camera department (total time)?